Replace a Word with Asterisks in a Sentence in Java

In this article, we will learn how to replace a specific word in a sentence with asterisks using Java. This technique can be useful for obscuring certain words in a text for privacy or censorship purposes.

Problem Statement

Develop a program in Java that takes a sentence and a word to be censored as input, then outputs the sentence with the specified word replaced by asterisks, while preserving the original format of the sentence.

Input

This is a sample only, the sky is blue, water is transparent

Output

This is a ****** only, the sky is blue, water is transparent

Steps to replace a word with asterisks in a sentence

• START.
• Define a function replace_word that accepts a sentence and a target word.
• Use a regular expression to split the sentence into an array of words based on whitespace.
• Create a string of asterisks with the same length as the word to be replaced.
• Iterate through the array of words using a for loop, replacing any occurrence of the target word with the asterisk string.
• Combine the words back into a single string, maintaining the original spacing.
• Print the modified sentence to the console.
• STOP

Java program to replace a word with asterisks in a sentence

To replace a word with asterisks in a sentence, the Java program is as follows ?

public class Demo{
 static String replace_word(String sentence, String pattern){
String[] word_list = sentence.split("\s+");
String my_result = "";
String asterisk_val = "";
for (int i = 0; i < pattern.length(); i++)
asterisk_val += '*';
int my_index = 0;
for (String i : word_list){
 if (i.compareTo(pattern) == 0)
  word_list[my_index] = asterisk_val;
 my_index++;
}
for (String i : word_list)
   my_result += i + ' ';
return my_result;
 }
 public static void main(String[] args){
String sentence = "This is a sample only, the sky is blue, water is transparent ";
String pattern = "sample";
System.out.println(replace_word(sentence, pattern));
 }
}

Output

This is a ****** only, the sky is blue, water is transparent

Code Explanation

A class named Demo contains a function named replace_word that takes the sentence and the pattern as parameters. A sentence is split and stored in a string array. An empty string is defined, and the pattern is iterated over, based on its length. An asterisk value is defined as * and for every character in the sentence, the character is compared to the pattern, and a specific occurrence is replaced with the asterisk symbol. The final string is displayed on the console.